YOu cannot get them from the Java servlet (Java servlet code not used to read dialog fields) - they are read using JS as described in the article.
However - if you are using HTL - then a class that extends WCMUSePojo can read dialog fields. See:
http://scottsdigitalcommunity.blogspot.ca/2016/07/creating-aem-html-template-language.html
For example:
currentNode.getProperty(
"./jcr:tocity"
).getString();
Hope this helps.